WOMS
U code network High severity

U0135 Lost Communication With Differential Control Module Front

The OBD2 code U0135 indicates that there is a loss of communication between the vehicle's main control module and the differential control module located at the front of the vehicle

Definition

The OBD2 code U0135 indicates that there is a loss of communication between the vehicle's main control module and the differential control module located at the front of the vehicle

Common causes

  • Faulty differential control module
  • Wiring issues (damaged, frayed, or corroded wires)
  • Poor connections or loose connectors
  • Faulty CAN bus communication
  • Blown fuses
  • Software issues or programming errors
  • Electrical interference or shorts in the system

Common misdiagnoses

  • Faulty Differential Control Module
  • Wiring issues or damaged connectors
  • Faulty Body Control Module (BCM)
  • Faulty Engine Control Module (ECM)
  • Issues with the CAN bus system
  • Low battery voltage or power supply issues
  • Faulty wheel speed sensors
  • Incorrectly diagnosed transmission issues

Troubleshooting steps

  1. 1. Check for Other Codes

    Use an OBD-II scanner to check for any additional trouble codes. Sometimes, multiple codes can provide more context about the issue

  2. 2. Inspect Wiring and Connectors

    Visual Inspection: Check the wiring harness and connectors related to the differential control module for any signs of damage, corrosion, or loose connections

  3. 3. Connector Pins

    Ensure that the pins in the connectors are not bent, corroded, or damaged

  4. 4. Test the Differential Control Module

    Power and Ground: Verify that the differential control module is receiving the correct power and ground signals. Use a multimeter to check voltage and ground continuity

  5. 5. Module Functionality

    If possible, test the differential control module in another vehicle or replace it with a known good unit to see if the problem persists

  6. 6. Check Communication Lines

    CAN Bus: Since the differential control module communicates over the CAN bus, check the integrity of the CAN bus wiring. Look for shorts, opens, or high resistance in the communication lines

  7. 7. Termination Resistors

    Ensure that the CAN bus termination resistors are present and functioning correctly

  8. 8. Inspect Related Modules

    Other modules in the vehicle may also affect communication. Check for codes or issues in related modules (e.g., ABS, transfer case control module) that may be causing communication problems

  9. 9. Perform a Network Test

    Use a scan tool capable of performing a network test to check for communication between modules. This can help identify if the issue is isolated to the differential control module or if it’s a broader communication issue

  10. 10. Check for Software Updates

    Sometimes, software glitches can cause communication issues. Check with the manufacturer for any available software updates for the vehicle’s control modules

  11. 11. Clear Codes and Test Drive

    After performing the above checks and repairs, clear the trouble codes and take the vehicle for a test drive to see if the code returns

  12. 12. Consult Technical Service Bulletins (TSBs)

    Look for any TSBs related to the U0135 code for your specific vehicle make and model. Manufacturers may have issued guidance or fixes for known issues

  13. 13. Seek Professional Help

    If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician who has experience with your vehicle’s specific systems. By following these troubleshooting steps, you can systematically identify and resolve the issue related to the U0135 code